Switching oil damper with built-in controller for structural control

This paper presents a simple semiactive oil damper developed for an actual application. This device can dissipate twice as much energy imposed by wind or earthquake forces as an ordinary passive damper by switching the opening of the on/off valve according to a signal from a controller. Because the system employs a decentralized control algorithm that uses only a built-in sensors' information, each device can be equipped with all the necessary control equipment such as sensors and a controller. This simple construction has several advantages in actual application. First, we discuss the control algorithm and compare the control performance with that of the passive damper. Second, we describe the construction of the developed full-scale device. Finally, we present the results of a dynamic loading test conducted on a full-scale device. The developed device showed stable performance under a nonstationary excitation as well as a harmonic loading, and the improved energy dissipation capacity was clearly recognized. It is also confirmed that the damper's dynamic behavior can be accurately simulated with simple analytical parameters.